ui: scratchpad reinit

packages/ui-default/package.json

@@ -1,14 +1,11 @@
 {
   "name": "@hydrooj/ui-default",
-  "version": "4.39.14",
+  "version": "4.39.15",
   "author": "undefined <i@undefined.moe>",
   "license": "AGPL-3.0",
   "main": "hydro.js",
   "repository": "https://github.com/hydro-dev/Hydro.git",
   "preferUnplugged": true,
-  "scripts": {
-    "lint": "eslint"
-  },
   "devDependencies": {
     "@blueprintjs/core": "^4.9.3",
     "@fontsource/dm-mono": "^4.5.9",

packages/ui-default/pages/problem_detail.page.jsx

@@ -149,15 +149,15 @@ const page = new NamedPage(['problem_detail', 'contest_detail_problem', 'homewor
       });
     };
 
-    const root = createRoot($('#scratchpad').get(0));
     renderReact = () => {
+      const root = createRoot($('#scratchpad').get(0));
       root.render(
         <Provider store={store}>
           <ScratchpadApp />
         </Provider>,
       );
+      unmountReact = () => root.unmount();
     };
-    unmountReact = () => root.unmount();
     reactLoaded = true;
     $('.loader-container').hide();
   }